You do get a choice...but they pick places to chose from. It always depends on what his job will be. Its a hard lifestyle. Navy is pretty good about not sending the ships out a lot. Most of the time its one 6 month deployment every 18 months (but thats subs). I used to be a navy wife with a kid. If you ever need to talk...just let me know
To answer your other question: If he is stationed overseas you will more than likely go with him. If hes just going to school overseas, you will probably just stay wherever you are...